safety fix
improve error message on failing exec()
clean up exec() code a little
implement tuple compatibility form of Py2 exec statement
extended test case
clean up exec test file
make a couple of parser errors non-fatal to keep parsing
externalise some utility code functions
externalise some utility code functions
fix build
Faster list setting when bounds check and wrapparound are disabled.
Another doc fix.
Fix docs about non-extern variables in pxd files.
changelog

--HG--
extra : rebase_source : ca6bbd2378e2e67004b236da8a67e6b607aa0ae2
implement 'raise ... from None' in Py3.3

--HG--
extra : rebase_source : 9ad9c4ea052a3eae0888f02a07ba4c40d62ddddf
ignore 'raise ... from None' in Py<3.3
add tests for 'raise ... from None'
changelog
support Python string constants in utility code
use Python string constant in __Pyx_PyObject_Append()